California Code, Streets and Highways Code - SHC § 27177

The California Highway Patrol shall have the authority and it shall be its duty to provide for proper and adequate policing of all facilities of travel constructed by the district, to insure the enforcement thereon of the Vehicle Code and of any other law relating to the use and operation of vehicles upon highways or vehicular crossings as defined in the Vehicle Code, and of the rules and regulations adopted by the board of directors of the district in respect to facilities of travel and parking areas, and to cooperate with the district, to the end that such facilities of travel and parking areas be operated at all times in such manner as to carry traffic efficiently.This authority of the California Highway Patrol is exclusive except as to the authority conferred upon the district by Section 27174.1 in respect to those facilities of travel or parking areas.

All required accident reports and supplemental reports, and all other reports made to the California Highway Patrol by any peace officer, member of the California Highway Patrol, or other employees of the Department of Motor Vehicles and California Highway Patrol relative to accidents and incidents occurring on property of a bridge and highway district shall be immediately available for the confidential use of the district.